Missing my ex’s dog more than him. How to cope? ?

Sadly the law treats dogs as property, and you don't have a legal claim on the dog if you're not the legal owner. Not even if you can show that you're the better owner.

Anyone who gets a dog just to breed and sell puppies and thinks of it as an easy way to make money shouldn't either own a dog or be breeding a dog. Proper dog breeders do a lot more work than just letting their dog get knocked up.

Your best bet is to offer to buy her if you are actually able to keep her. You need to pay him something so that there will be no question in the future that she is now yours. But you can't make him do this.

Option two is to offer to look after her whenever he wants to go away on holidays, and play a "long game". His kids will eventually get tired of the dog, and she will get too old for puppies. Then you offer to take her. She will probably still be middle-aged (for a dog) when he realises he doesn't want her any more. You will then have many happy years with her.

The problem here is that if the relationship was toxic and he realises how you feel about this dog he may exploit the situation to get back at you. He has this poor dog in his power, but he really doesn't care about her, whereas you do. Do you think he would mistreat this dog to hurt you? If so your best option is to hide your feelings.

Option three is to get another dog, preferably an adult rescue dog. Look for one who is dog friendly, in case your ex's dog comes back into your life again. Another possibility is to get one of your ex's dog's puppies.

Don't get over it! Offer to buy the dog from him! Tell him everything you told us about how close you have grown to him/her; and maybe he will agree that owning a dog is too much work for him (if he is not a dog person to begin with). You really do have a high chance of having this dog becoming your permanent pet. All the best!

I suggest you not get over it and do what it takes to get custody of that dog.  He will not do for the dog what you did and I guarantee you that that dog misses you just as  much as you miss it.

If you have records of you caring for the dog, including paying for it's food and vet bills, you have a claim on the dog.

But think long and hard about how that relationship ended before pursuing this  and also about your ability to care for the dog if you were to get custody.  What is best for the dog?

Hahahh this is hilarious!!

Would he be willing to give the dog to you?  Offer to buy her from him.

Ask him if you can have the dog.